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Digital Inputs (201..204)

There are four digital inputs, numbered 5..8. The inputs contain a Schmitt trigger circuit and therefore have a
hysteresis: the digital level goes from '0' to '1' at 1.5V while remains '1' until the voltage drops below 0.75V.
The inputs are identical to those of Type I. See

Digital Inputs (101..104)

for a detailed description of the

specifications.

Digital Outputs (Group 201 and 202)

For optimal flexibility, the digital outputs are separated into two groups: Group 201 and 202. The output
voltage corresponding to a '1' can be programmed separately for group 201. Group 202 has open drain
outputs meaning that 'configuration' of the '1' output level must be done via an external pull-up resistor if
necessary. The 4 output bits of Group 202 are located on the same connector locations as digital inputs
201..204.

See

Digital Outputs (Group 101 and 102)

for a detailed description of the specifications: Group 201 shares

the specification of Group 101 and Group 202 shares those of Group 102.

Bi-Directional Digital I/O

With the eC-test-mate Type II, it is possible to test up to 4 bi-directional digital signals.

As described in previous section, the 4 output bits of Group 202 are located on the same connector
locations as digital inputs 201..204. Since the outputs are open-collector outputs, the line can be left floating
by setting the output to '0'. A pull-up resistor shall be present on the UUT.

Serial Channel (UART 201)

The serial channel (numbered as '201') is designed to work with signal levels up to 5V. The actual output
voltage is determined by the voltage that is applied to the UART_VCC test pin as long as this voltage is
equal or less than 5V. For higher voltages, the Serial channel is fixed at 5V.

UART_VCC (input)

This pin determines the logic '1' level of the UART_TX output and MUST BE CONNECTED to the appropriate
voltage on the UUT.
Typical working voltage range is 1.7..5.0V. Absolute maximum voltage is 24V.
The current drawn from this pin consists of a quiescent current of about 4µA.

The UART_TX (output)

The transmit output is driven by a level shifter (SN74LVC1T45) with a series resistor of 100 Ω. This means
that the sink and source current of the output is limited.

UART_RX (input)

The Serial input has a fixed VIHmin of 1.7V, independent of the voltage that is applied to the UART_VCC
input.

Note 1: The UART_VCC test pin must be connected on the UUT to a voltage that corresponds with the
logic '1' level of the serial interface. If left open, the UART_TX output will NOT work.

Note 2: The internal eC-test-mate UART is shared between the UART test pins and the RS485 test pins.
Depending on the last configuration command, either the UART pins or RS485 pins will be active.
Inactivity for the UART TX pin is defined as a constant '1' level.

See

Serial Channel (UART 101)

for the configurable parameters (baud rate etc).